November 17, 2013

Static-99 “norms du jour” get yet another makeover

It would be humorous if the real-world consequences were not so grave.

Every
year, at a jam-packed session of the annual conference of the
Association for the Treatment of Sexual Abusers (ATSA), the developers
of the Static-99 family of actuarial risk assessment tools roll out yet a
new methodology to replace the old.

This
year, they announced that they are scrapping two of three
sets of "non-routine" comparison norms that they introduced at an ATSA
conference just four years ago. Stay tuned, they told their rapt
audience, for further instructions on how to choose between the
two remaining sets of norms.

To many, this might sound dry and technical. But in the courtroom
trenches, sexually violent predator cases often hinge on an evaluator's
choice of a comparison group. Should the offender be compared with the
full population of convicted sex offenders? Or a subset labeled "high
risk/needs" that offended at a rate more than 3.5 times higher than the
more representative group (21 percent versus 6 percent after five
years)?

To illustrate, whereas only about 3 percent (4 out of 139)of the men over 70
in the combined Static-99R samples reoffended, invoking the high-risk
norms would cause a septuagenarian's risk to skyrocket by 400 percent. It's
not hard to see why such an inflated estimate might increase the odds
of a judge or jury finding a former offender to be dangerous, and recommending
indefinite detention.

The
first problem with this method is that the basis for choosing a
comparison group is very vague, inviting bias on the part of forensic evaluators. Even more essentially, there is not a shred of empirical
evidence that choosing the high-risk norms improves decision-making
accuracy in sexually violent predator (SVP) cases.

That
should come as no surprise. Not one of the six samples that were
cobbled together post-hoc to create the high-risk norms included anyone who was civilly committed -- or considered for commitment -- under modern-day SVP laws, which now exist in 20 U.S. states. (Four samples are
Canadian, one is Danish, and the only American one is an exceptionally
high-risk, archaic and idiosyncratic sample from an infamous psychiatric
facility in Bridgewater, Massachusetts.)

A
typical psychological test has a published manual that gives
instructions on proper use and clearly describes its norms. In contrast,
the Static-99, despite its high-stakes deployment, has no published
manual. Its users must rely on a website, periodic conferences and
training sessions, and word-of-mouth information.

High-risk norms based on guesswork, say forensic psychologists

Now,
two forensic psychologists have joined a growing chorus of mainstream
practitioners cautioning against the use of the high-risk norms, unless
and until research proves that they improve evaluators' accuracy in
forecasting risk of sexual re-offense.

"There
is zero empirical research showing increased accuracy by switching to a
non- representative group," note Gregory DeClue and Denis Zavodny in an article just published in the Open Access Journal of Forensic Psychology. "Unless and until such choices are found to increase the accuracy of
risk assessments, forensic evaluators should use local norms (if
available) or the FULLPOP* comparison group (considered roughly
representative of all adjudicated sex offenders)."

The
authors critiqued the growing practice of selecting the high-risk norms
based on so-called "psychologically meaningful risk factors." The
Static-99 developers’ recommendation for this clinical decision-making is based on mere
guesswork or speculation that is contradicted by scientific evidence
from at least five recent studies, they note.

"In
theory, it is possible that a standardized procedure could be developed
whereby evaluators would use a dynamic risk-assessment tool in addition
to a static-factor tool such as the Static-99R. Next, it could be
tested whether carefully trained evaluators in a controlled study, using
that combination of tools, arrive at more accurate predictions…. A
third step would be field studies to address the practical impact of
using the combination procedure in actual cases. Even if well-trained
evaluators could use the procedure effectively under controlled
conditions, it would be important to explore whether allegiance or other
social-psychological factors decrease the accuracy of risk assessments
in forensic cases. At present, there is no research showing that
incremental validity is added by using clinical judgment regarding
‘external psychologically meaningful risk factors’ to augment or
facilitate a statistically based risk- assessment scheme."

Indeed,
an empirical study last year of Static-99 risk predictions found
that accuracy decreased when evaluators used clinical judgment to
override actuarial scores.

"The
ratings with overrides predicted recidivism in the wrong direction --
that is, clinical overrides of increased risk were actually associated
with lower recidivism rates and vice versa,” wrote Jennifer Storey,
Kelly Watt, Karla Jackson and Stephen Hart in an article in Sexual Abuse: Journal of Research and Treatment.

DeClue
and Zavodny question the Static-99 developers' decision to report only 5-year recidivism data, rather than also include 10-year recidivism rates, for the full sample, even though such information
is readily available. This decision may influence some evaluators to go
to the high-risk norms, for which 10-year data are reported, as the
reference group for an offender.

The
absolute best practice, they note, is to compare an offender with the
actual recidivism rates in the local jurisdiction. To facilitate this, they provide a chart of contemporary recidivism rates from several U.S. states, including California,
Washington, Texas, Florida, Connecticut, New Jersey, Minnesota and South
Carolina. Recidivism rates varied from a low of less than 1 percent,
among supervised offenders in Texas, all the way up to 25% for a group
of offenders in Washington.

As
I reported last month on the new research out of Florida, a growing body of
research is establishing that detected recidivism is far lower than was
originally reported by the Static-99 developers. I predict that the
high-risk samples will eventually fall by the wayside, as have other
unscientifically proven methods.

But
even if this suspect procedure is discredited and abandoned by the
actuarial gurus who originally introduced it, this will not provide automatic
redress for those already detained under the debunked method.

There's got to be a saner way to protect the public from sexual predators.

*NOTE: DeClue and Zavodny
replaced the developer’s label of the full group as "routine" with the
term FULLPOP, for full population, after hearing evaluators testify in
court that they did not use the full norms because they did not consider
the individual in question to be "a routine sex offender."

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Karen Franklin, Ph.D. is a forensic psychologist and adjunct professor at Alliant University in Northern California. She is a former criminal investigator and legal affairs reporter. See her website for more professional background. If you find this blog's content helpful, you may subscribe to its digest version (via "subscribe" box, above) to automatically receive new posts.

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